<style type="text/css">
  .first {
    height:400px;
    background-color: red;
    will-change: transform;
  }

  .second {
    left: 100px;
    bottom: 0px; 
    background-color:blue;
    width:7px;
    height:562px;
    position: absolute; transform: translateX(0)
  }

  .outer {
    overflow: scroll;
    /* FIXME: make this height: 500px to expose another bug */
    height: 600px;
    width: 500px;
    position: absolute;
    bottom:10px;
    background-color: grey;
  }
</style>
<div class="outer">
  <div class="first"> </div>
  <div class="second"> </div>
</div>